Breakthrough: Robotic limbs moved by the mind

The following script is from "Breakthrough" which aired on Dec. 30, 2012 and rebroadcast on June 2, 2013. Scott Pelley is the correspondent. Denise Schrier Cetta, producer.

In a decade of war, more than 1,300 Americans have lost limbs on the battlefield. And that fact led the Department of Defense to start a crash program to help veterans and civilians by creating an artificial arm and hand that are amazingly human. But that's not the breakthrough. We don't use that word very often because it's overused. But when you see how they have connected this robotic limb to a human brain, you'll understand why we made an exception.

As we reported last December, to take this ultimate step they had to find a person willing to have brain surgery to explore new frontiers of what it is to be human. That person would have to be an explorer with desperate need, remarkable courage and maybe most of all, a mind that is game.

The person they chose is Jan Scheuermann, a Pittsburgh mother of two and writer, with a mind nimble enough to match wits on "The Wheel of Fortune" in 1995.

When her mind triumphed her brain sent signals of delight to every muscle in her body. But a year after this moment, those brain signals were being cut off.

Jan Scheuermann: One day, I had trouble in the evening, I was making a lot of trips in and out of the car. It felt like my legs were dragging behind me.

Within two years a genetic disease called spinocerebellar degeneration broke the connection between brain and body. Now, at age 53, Jan Scheurmann can move only the muscles in her face and a few in her neck -- she's dependent on a caregiver for nearly all of her daily needs.

{Mother: 52 Across.]

And her mother to help her solve the puzzles she loves.

[Mom: Healed?

Jan Scheuermann: Oh, oh, you're good.

At the same time, Jan Scheuermann was putting her mind to a new life, a neuroscientist, just across town, at the University of Pittsburgh, was imagining how people like Jan might be restored.

Andy Schwartz, on the right, is working on an ambitious Defense Department project called "Revolutionizing Prosthetics."

Five years ago, we visited his lab and Schwartz showed us how he implanted tiny sensors like this one into the brains of monkeys and then wired them to a crude robotic arm.

Schwartz told us that, when the monkey thinks about moving his own arm, his brain cells, or neurons, fire off electrical signals. The sensor in his brain can pick up these signals and send them to the robot.

Scott Pelley: So he's operating the arm in three dimensions, up, down, forward and back?

Andy Schwartz: As well as the gripper.

Scott Pelley: What you're telling me is that the monkey is operating this arm with nothing but his thoughts?

Andy Schwartz: Absolutely.

Scott Pelley: What are the chances that a human being would be able to do this same thing?

Andy Schwartz: Oh, we think a human being could do much better.

That conversation was in 2008. And since then, the $150 million Revolutionizing Prosthetics program has reached farther than most thought possible.